/* SPDX-License-Identifier: GPL-2.0-only */ /* * Based on arch/arm/include/asm/tlbflush.h * * Copyright (C) 1999-2003 Russell King * Copyright (C) 2012 ARM Ltd. */ #ifndef __ASM_TLBFLUSH_H #define __ASM_TLBFLUSH_H #ifndef __ASSEMBLY__ #include #include #include #include #include #include /* * Raw TLBI operations. * * Where necessary, use the __tlbi() macro to avoid asm() * boilerplate. Drivers and most kernel code should use the TLB * management routines in preference to the macro below. * * The macro can be used as __tlbi(op) or __tlbi(op, arg), depending * on whether a particular TLBI operation takes an argument or * not. The macros handles invoking the asm with or without the * register argument as appropriate. */ #define __TLBI_0(op, arg) asm (ARM64_ASM_PREAMBLE \ "tlbi " #op "\n" \ ALTERNATIVE("nop\n nop", \ "dsb ish\n tlbi " #op, \ ARM64_WORKAROUND_REPEAT_TLBI, \ CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \ : : ) #define __TLBI_1(op, arg) asm (ARM64_ASM_PREAMBLE \ "tlbi " #op ", %0\n" \ ALTERNATIVE("nop\n nop", \ "dsb ish\n tlbi " #op ", %0", \ ARM64_WORKAROUND_REPEAT_TLBI, \ CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \ : : "r" (arg)) #define __TLBI_N(op, arg, n, ...) __TLBI_##n(op, arg) #define __tlbi(op, ...) __TLBI_N(op, ##__VA_ARGS__, 1, 0) #define __tlbi_user(op, arg) do { \ if (arm64_kernel_unmapped_at_el0()) \ __tlbi(op, (arg) | USER_ASID_FLAG); \ } while (0) /* This macro creates a properly formatted VA operand for the TLBI */ #define __TLBI_VADDR(addr, asid) \ ({ \ unsigned long __ta = (addr) >> 12; \ __ta &= GENMASK_ULL(43, 0); \ __ta |= (unsigned long)(asid) << 48; \ __ta; \ }) /* * Get translation granule of the system, which is decided by * PAGE_SIZE. Used by TTL. * - 4KB : 1 * - 16KB : 2 * - 64KB : 3 */ #define TLBI_TTL_TG_4K 1 #define TLBI_TTL_TG_16K 2 #define TLBI_TTL_TG_64K 3 static inline unsigned long get_trans_granule(void) { switch (PAGE_SIZE) { case SZ_4K: return TLBI_TTL_TG_4K; case SZ_16K: return TLBI_TTL_TG_16K; case SZ_64K: return TLBI_TTL_TG_64K; default: return 0; } } /* * Level-based TLBI operations. * * When ARMv8.4-TTL exists, TLBI operations take an additional hint for * the level at which the invalidation must take place. If the level is * wrong, no invalidation may take place. In the case where the level * cannot be easily determined, a 0 value for the level parameter will * perform a non-hinted invalidation. * * For Stage-2 invalidation, use the level values provided to that effect * in asm/stage2_pgtable.h. */ #define TLBI_TTL_MASK GENMASK_ULL(47, 44) #define __tlbi_level(op, addr, level) do { \ u64 arg = addr; \ \ if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \ level) { \ u64 ttl = level & 3; \ ttl |= get_trans_granule() << 2; \ arg &= ~TLBI_TTL_MASK; \ arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \ } \ \ __tlbi(op, arg); \ } while(0) #define __tlbi_user_level(op, arg, level) do { \ if (arm64_kernel_unmapped_at_el0()) \ __tlbi_level(op, (arg | USER_ASID_FLAG), level); \ } while (0) /* * This macro creates a properly formatted VA operand for the TLB RANGE. * The value bit assignments are: * * +----------+------+-------+-------+-------+----------------------+ * | ASID | TG | SCALE | NUM | TTL | BADDR | * +-----------------+-------+-------+-------+----------------------+ * |63 48|47 46|45 44|43 39|38 37|36 0| * * The address range is determined by below formula: * [BADDR, BADDR + (NUM + 1) * 2^(5*SCALE + 1) * PAGESIZE) * */ #define __TLBI_VADDR_RANGE(addr, asid, scale, num, ttl) \ ({ \ unsigned long __ta = (addr) >> PAGE_SHIFT; \ __ta &= GENMASK_ULL(36, 0); \ __ta |= (unsigned long)(ttl) << 37; \ __ta |= (unsigned long)(num) << 39; \ __ta |= (unsigned long)(scale) << 44; \ __ta |= get_trans_granule() << 46; \ __ta |= (unsigned long)(asid) << 48; \ __ta; \ }) /* These macros are used by the TLBI RANGE feature. */ #define __TLBI_RANGE_PAGES(num, scale) \ ((unsigned long)((num) + 1) << (5 * (scale) + 1)) #define MAX_TLBI_RANGE_PAGES __TLBI_RANGE_PAGES(31, 3) /* * Generate 'num' values from -1 to 30 with -1 rejected by the * __flush_tlb_range() loop below. */ #define TLBI_RANGE_MASK GENMASK_ULL(4, 0) #define __TLBI_RANGE_NUM(pages, scale) \ ((((pages) >> (5 * (scale) + 1)) & TLBI_RANGE_MASK) - 1) /* * TLB Invalidation * ================ * * This header file implements the low-level TLB invalidation routines * (sometimes referred to as "flushing" in the kernel) for arm64. * * Every invalidation operation uses the following template: * * DSB ISHST // Ensure prior page-table updates have completed * TLBI ... // Invalidate the TLB * DSB ISH // Ensure the TLB invalidation has completed * if (invalidated kernel mappings) * ISB // Discard any instructions fetched from the old mapping * * * The following functions form part of the "core" TLB invalidation API, * as documented in Documentation/core-api/cachetlb.rst: * * flush_tlb_all() * Invalidate the entire TLB (kernel + user) on all CPUs * * flush_tlb_mm(mm) * Invalidate an entire user address space on all CPUs. * The 'mm' argument identifies the ASID to invalidate. * * flush_tlb_range(vma, start, end) * Invalidate the virtual-address range '[start, end)' on all * CPUs for the user address space corresponding to 'vma->mm'. * Note that this operation also invalidates any walk-cache * entries associated with translations for the specified address * range. * * flush_tlb_kernel_range(start, end) * Same as flush_tlb_range(..., start, end), but applies to * kernel mappings rather than a particular user address space. * Whilst not explicitly documented, this function is used when * unmapping pages from vmalloc/io space. * * flush_tlb_page(vma, addr) * Invalidate a single user mapping for address 'addr' in the * address space corresponding to 'vma->mm'. Note that this * operation only invalidates a single, last-level page-table * entry and therefore does not affect any walk-caches. * * * Next, we have some undocumented invalidation routines that you probably * don't want to call unless you know what you're doing: * * local_flush_tlb_all() * Same as flush_tlb_all(), but only applies to the calling CPU. * * __flush_tlb_kernel_pgtable(addr) * Invalidate a single kernel mapping for address 'addr' on all * CPUs, ensuring that any walk-cache entries associated with the * translation are also invalidated. * * __flush_tlb_range(vma, start, end, stride, last_level) * Invalidate the virtual-address range '[start, end)' on all * CPUs for the user address space corresponding to 'vma->mm'. * The invalidation operations are issued at a granularity * determined by 'stride' and only affect any walk-cache entries * if 'last_level' is equal to false. * * * Finally, take a look at asm/tlb.h to see how tlb_flush() is implemented * on top of these routines, since that is our interface to the mmu_gather * API as used by munmap() and friends. */ static inline void local_flush_tlb_all(void) { dsb(nshst); __tlbi(vmalle1); dsb(nsh); isb(); } static inline void flush_tlb_all(void) { dsb(ishst); __tlbi(vmalle1is); dsb(ish); isb(); } static inline void flush_tlb_mm(struct mm_struct *mm) { unsigned long asid; dsb(ishst); asid = __TLBI_VADDR(0, ASID(mm)); __tlbi(aside1is, asid); __tlbi_user(aside1is, asid); dsb(ish); mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL); } static inline void __flush_tlb_page_nosync(struct mm_struct *mm, unsigned long uaddr) { unsigned long addr; dsb(ishst); addr = __TLBI_VADDR(uaddr, ASID(mm)); __tlbi(vale1is, addr); __tlbi_user(vale1is, addr); mmu_notifier_arch_invalidate_secondary_tlbs(mm, uaddr & PAGE_MASK, (uaddr & PAGE_MASK) + PAGE_SIZE); } static inline void flush_tlb_page_nosync(struct vm_area_struct *vma, unsigned long uaddr) { return __flush_tlb_page_nosync(vma->vm_mm, uaddr); } static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) { flush_tlb_page_nosync(vma, uaddr); dsb(ish); } static inline bool arch_tlbbatch_should_defer(struct mm_struct *mm) { #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI /* * TLB flush deferral is not required on systems which are affected by * ARM64_WORKAROUND_REPEAT_TLBI, as __tlbi()/__tlbi_user() implementation * will have two consecutive TLBI instructions with a dsb(ish) in between * defeating the purpose (i.e save overall 'dsb ish' cost). */ if (unlikely(cpus_have_const_cap(ARM64_WORKAROUND_REPEAT_TLBI))) return false; #endif return true; } static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, struct mm_struct *mm, unsigned long uaddr) { __flush_tlb_page_nosync(mm, uaddr); } /* * If mprotect/munmap/etc occurs during TLB batched flushing, we need to * synchronise all the TLBI issued with a DSB to avoid the race mentioned in * flush_tlb_batched_pending(). */ static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm) { dsb(ish); } /* * To support TLB batched flush for multiple pages unmapping, we only send * the TLBI for each page in arch_tlbbatch_add_pending() and wait for the * completion at the end in arch_tlbbatch_flush(). Since we've already issued * TLBI for each page so only a DSB is needed to synchronise its effect on the * other CPUs. * * This will save the time waiting on DSB comparing issuing a TLBI;DSB sequence * for each page. */ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) { dsb(ish); } /* * This is meant to avoid soft lock-ups on large TLB flushing ranges and not * necessarily a performance improvement. */ #define MAX_TLBI_OPS PTRS_PER_PTE static inline void __flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end, unsigned long stride, bool last_level, int tlb_level) { int num = 0; int scale = 0; unsigned long asid, addr, pages; start = round_down(start, stride); end = round_up(end, stride); pages = (end - start) >> PAGE_SHIFT; /* * When not uses TLB range ops, we can handle up to * (MAX_TLBI_OPS - 1) pages; * When uses TLB range ops, we can handle up to * (MAX_TLBI_RANGE_PAGES - 1) pages. */ if ((!system_supports_tlb_range() && (end - start) >= (MAX_TLBI_OPS * stride)) || pages >= MAX_TLBI_RANGE_PAGES) { flush_tlb_mm(vma->vm_mm); return; } dsb(ishst); asid = ASID(vma->vm_mm); /* * When the CPU does not support TLB range operations, flush the TLB * entries one by one at the granularity of 'stride'. If the TLB * range ops are supported, then: * * 1. If 'pages' is odd, flush the first page through non-range * operations; * * 2. For remaining pages: the minimum range granularity is decided * by 'scale', so multiple range TLBI operations may be required. * Start from scale = 0, flush the corresponding number of pages * ((num+1)*2^(5*scale+1) starting from 'addr'), then increase it * until no pages left. * * Note that certain ranges can be represented by either num = 31 and * scale or num = 0 and scale + 1. The loop below favours the latter * since num is limited to 30 by the __TLBI_RANGE_NUM() macro. */ while (pages > 0) { if (!system_supports_tlb_range() || pages % 2 == 1) { addr = __TLBI_VADDR(start, asid); if (last_level) { __tlbi_level(vale1is, addr, tlb_level); __tlbi_user_level(vale1is, addr, tlb_level); } else { __tlbi_level(vae1is, addr, tlb_level); __tlbi_user_level(vae1is, addr, tlb_level); } start += stride; pages -= stride >> PAGE_SHIFT; continue; } num = __TLBI_RANGE_NUM(pages, scale); if (num >= 0) { addr = __TLBI_VADDR_RANGE(start, asid, scale, num, tlb_level); if (last_level) { __tlbi(rvale1is, addr); __tlbi_user(rvale1is, addr); } else { __tlbi(rvae1is, addr); __tlbi_user(rvae1is, addr); } start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT; pages -= __TLBI_RANGE_PAGES(num, scale); } scale++; } dsb(ish); mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end); } static inline void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { /* * We cannot use leaf-only invalidation here, since we may be invalidating * table entries as part of collapsing hugepages or moving page tables. * Set the tlb_level to 0 because we can not get enough information here. */ __flush_tlb_range(vma, start, end, PAGE_SIZE, false, 0); } static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end) { unsigned long addr; if ((end - start) > (MAX_TLBI_OPS * PAGE_SIZE)) { flush_tlb_all(); return; } start = __TLBI_VADDR(start, 0); end = __TLBI_VADDR(end, 0); dsb(ishst); for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12)) __tlbi(vaale1is, addr); dsb(ish); isb(); } /* * Used to invalidate the TLB (walk caches) corresponding to intermediate page * table levels (pgd/pud/pmd). */ static inline void __flush_tlb_kernel_pgtable(unsigned long kaddr) { unsigned long addr = __TLBI_VADDR(kaddr, 0); dsb(ishst); __tlbi(vaae1is, addr); dsb(ish); isb(); } #endif #endif